How to Manage Pests
UC Pest Management Guidelines
The saltmarsh caterpillar is most abundant in August and September, but damaging populations are sporadic. Eggs are spherical, whitish, somewhat flattened, about 3/100 inch (0.75 mm) in diameter, and found in naked clusters on the undersurface of leaves. Young larvae are hairy and gray when first hatched, then darken to yellow, brownish, or almost black with yellow lines. They are covered with reddish or black hairs and can be up to 2 inches long when fully grown. Young larvae feed in groups, but as they grow they disperse and start feeding individually.
Damage by saltmarsh caterpillar consists primarily of defoliation.
Start inspecting plants for saltmarsh caterpillar damage along with other pests and their damage during the vegetative growth stage; continue to monitor these caterpillars from bud to blossom and during the pod fill period. Specific treatment thresholds have not been established for these foliage feeders. Late-season infestations are insignificant. If damaging numbers are encountered mid-season when excessive foliage loss may reduce crop production, a treatment may be warranted.
UC IPM Pest Management Guidelines: Dry